arch/arm/mm/init.c - kernel/msm - Gitiles

 /*
  *  linux/arch/arm/mm/init.c
  *
  *  Copyright (C) 1995-2002 Russell King
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
 #include <linux/config.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/ptrace.h>
 #include <linux/swap.h>
 #include <linux/init.h>
 #include <linux/bootmem.h>
 #include <linux/mman.h>
 #include <linux/nodemask.h>
 #include <linux/initrd.h>

 #include <asm/mach-types.h>
 #include <asm/hardware.h>
 #include <asm/setup.h>
 #include <asm/tlb.h>

 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>

 #define TABLE_SIZE	(2 * PTRS_PER_PTE * sizeof(pte_t))

 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);

 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 extern void _stext, _text, _etext, __data_start, _end, __init_begin, __init_end;
 extern unsigned long phys_initrd_start;
 extern unsigned long phys_initrd_size;

 /*
  * The sole use of this is to pass memory configuration
  * data from paging_init to mem_init.
  */
 static struct meminfo meminfo __initdata = { 0, };

 /*
  * empty_zero_page is a special page that is used for
  * zero-initialized data and COW.
  */
 struct page *empty_zero_page;

 void show_mem(void)
 {
 	int free = 0, total = 0, reserved = 0;
 	int shared = 0, cached = 0, slab = 0, node;

 	printk("Mem-info:\n");
 	show_free_areas();
 	printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));

 	for_each_online_node(node) {
 		struct page *page, *end;

 		page = NODE_MEM_MAP(node);
 		end  = page + NODE_DATA(node)->node_spanned_pages;

 		do {
 			total++;
 			if (PageReserved(page))
 				reserved++;
 			else if (PageSwapCache(page))
 				cached++;
 			else if (PageSlab(page))
 				slab++;
 			else if (!page_count(page))
 				free++;
 			else
 				shared += page_count(page) - 1;
 			page++;
 		} while (page < end);
 	}

 	printk("%d pages of RAM\n", total);
 	printk("%d free pages\n", free);
 	printk("%d reserved pages\n", reserved);
 	printk("%d slab pages\n", slab);
 	printk("%d pages shared\n", shared);
 	printk("%d pages swap cached\n", cached);
 }

 struct node_info {
 	unsigned int start;
 	unsigned int end;
 	int bootmap_pages;
 };

 #define O_PFN_DOWN(x)	((x) >> PAGE_SHIFT)
 #define O_PFN_UP(x)	(PAGE_ALIGN(x) >> PAGE_SHIFT)

 /*
  * FIXME: We really want to avoid allocating the bootmap bitmap
  * over the top of the initrd.  Hopefully, this is located towards
  * the start of a bank, so if we allocate the bootmap bitmap at
  * the end, we won't clash.
  */
 static unsigned int __init
 find_bootmap_pfn(int node, struct meminfo *mi, unsigned int bootmap_pages)
 {
 	unsigned int start_pfn, bank, bootmap_pfn;

 	start_pfn   = O_PFN_UP(__pa(&_end));
 	bootmap_pfn = 0;

 	for (bank = 0; bank < mi->nr_banks; bank ++) {
 		unsigned int start, end;

 		if (mi->bank[bank].node != node)
 			continue;

 		start = mi->bank[bank].start >> PAGE_SHIFT;
 		end   = (mi->bank[bank].size +
 			 mi->bank[bank].start) >> PAGE_SHIFT;

 		if (end < start_pfn)
 			continue;

 		if (start < start_pfn)
 			start = start_pfn;

 		if (end <= start)
 			continue;

 		if (end - start >= bootmap_pages) {
 			bootmap_pfn = start;
 			break;
 		}
 	}

 	if (bootmap_pfn == 0)
 		BUG();

 	return bootmap_pfn;
 }

 /*
  * Scan the memory info structure and pull out:
  *  - the end of memory
  *  - the number of nodes
  *  - the pfn range of each node
  *  - the number of bootmem bitmap pages
  */
 static unsigned int __init
 find_memend_and_nodes(struct meminfo *mi, struct node_info *np)
 {
 	unsigned int i, bootmem_pages = 0, memend_pfn = 0;

 	for (i = 0; i < MAX_NUMNODES; i++) {
 		np[i].start = -1U;
 		np[i].end = 0;
 		np[i].bootmap_pages = 0;
 	}

 	for (i = 0; i < mi->nr_banks; i++) {
 		unsigned long start, end;
 		int node;

 		if (mi->bank[i].size == 0) {
 			/*
 			 * Mark this bank with an invalid node number
 			 */
 			mi->bank[i].node = -1;
 			continue;
 		}

 		node = mi->bank[i].node;

 		/*
 		 * Make sure we haven't exceeded the maximum number of nodes
 		 * that we have in this configuration.  If we have, we're in
 		 * trouble.  (maybe we ought to limit, instead of bugging?)
 		 */
 		if (node >= MAX_NUMNODES)
 			BUG();
 		node_set_online(node);

 		/*
 		 * Get the start and end pfns for this bank
 		 */
 		start = mi->bank[i].start >> PAGE_SHIFT;
 		end   = (mi->bank[i].start + mi->bank[i].size) >> PAGE_SHIFT;

 		if (np[node].start > start)
 			np[node].start = start;

 		if (np[node].end < end)
 			np[node].end = end;

 		if (memend_pfn < end)
 			memend_pfn = end;
 	}

 	/*
 	 * Calculate the number of pages we require to
 	 * store the bootmem bitmaps.
 	 */
 	for_each_online_node(i) {
 		if (np[i].end == 0)
 			continue;

 		np[i].bootmap_pages = bootmem_bootmap_pages(np[i].end -
 							    np[i].start);
 		bootmem_pages += np[i].bootmap_pages;
 	}

 	high_memory = __va(memend_pfn << PAGE_SHIFT);

 	/*
 	 * This doesn't seem to be used by the Linux memory
 	 * manager any more.  If we can get rid of it, we
 	 * also get rid of some of the stuff above as well.
 	 *
 	 * Note: max_low_pfn and max_pfn reflect the number
 	 * of _pages_ in the system, not the maximum PFN.
 	 */
 	max_low_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET);
 	max_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET);

 	return bootmem_pages;
 }

 static int __init check_initrd(struct meminfo *mi)
 {
 	int initrd_node = -2;
 #ifdef CONFIG_BLK_DEV_INITRD
 	unsigned long end = phys_initrd_start + phys_initrd_size;

 	/*
 	 * Make sure that the initrd is within a valid area of
 	 * memory.
 	 */
 	if (phys_initrd_size) {
 		unsigned int i;

 		initrd_node = -1;

 		for (i = 0; i < mi->nr_banks; i++) {
 			unsigned long bank_end;

 			bank_end = mi->bank[i].start + mi->bank[i].size;

 			if (mi->bank[i].start <= phys_initrd_start &&
 			    end <= bank_end)
 				initrd_node = mi->bank[i].node;
 		}
 	}

 	if (initrd_node == -1) {
 		printk(KERN_ERR "initrd (0x%08lx - 0x%08lx) extends beyond "
 		       "physical memory - disabling initrd\n",
 		       phys_initrd_start, end);
 		phys_initrd_start = phys_initrd_size = 0;
 	}
 #endif

 	return initrd_node;
 }

 /*
  * Reserve the various regions of node 0
  */
 static __init void reserve_node_zero(unsigned int bootmap_pfn, unsigned int bootmap_pages)
 {
 	pg_data_t *pgdat = NODE_DATA(0);
 	unsigned long res_size = 0;

 	/*
 	 * Register the kernel text and data with bootmem.
 	 * Note that this can only be in node 0.
 	 */
 #ifdef CONFIG_XIP_KERNEL
 	reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start);
 #else
 	reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
 #endif

 	/*
 	 * Reserve the page tables.  These are already in use,
 	 * and can only be in node 0.
 	 */
 	reserve_bootmem_node(pgdat, __pa(swapper_pg_dir),
 			     PTRS_PER_PGD * sizeof(pgd_t));

 	/*
 	 * And don't forget to reserve the allocator bitmap,
 	 * which will be freed later.
 	 */
 	reserve_bootmem_node(pgdat, bootmap_pfn << PAGE_SHIFT,
 			     bootmap_pages << PAGE_SHIFT);

 	/*
 	 * Hmm... This should go elsewhere, but we really really need to
 	 * stop things allocating the low memory; ideally we need a better
 	 * implementation of GFP_DMA which does not assume that DMA-able
 	 * memory starts at zero.
 	 */
 	if (machine_is_integrator() || machine_is_cintegrator())
 		res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;

 	/*
 	 * These should likewise go elsewhere.  They pre-reserve the
 	 * screen memory region at the start of main system memory.
 	 */
 	if (machine_is_edb7211())
 		res_size = 0x00020000;
 	if (machine_is_p720t())
 		res_size = 0x00014000;

 #ifdef CONFIG_SA1111
 	/*
 	 * Because of the SA1111 DMA bug, we want to preserve our
 	 * precious DMA-able memory...
 	 */
 	res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;
 #endif
 	if (res_size)
 		reserve_bootmem_node(pgdat, PHYS_OFFSET, res_size);
 }

 /*
  * Register all available RAM in this node with the bootmem allocator.
  */
 static inline void free_bootmem_node_bank(int node, struct meminfo *mi)
 {
 	pg_data_t *pgdat = NODE_DATA(node);
 	int bank;

 	for (bank = 0; bank < mi->nr_banks; bank++)
 		if (mi->bank[bank].node == node)
 			free_bootmem_node(pgdat, mi->bank[bank].start,
 					  mi->bank[bank].size);
 }

 /*
  * Initialise the bootmem allocator for all nodes.  This is called
  * early during the architecture specific initialisation.
  */
 static void __init bootmem_init(struct meminfo *mi)
 {
 	struct node_info node_info[MAX_NUMNODES], *np = node_info;
 	unsigned int bootmap_pages, bootmap_pfn, map_pg;
 	int node, initrd_node;

 	bootmap_pages = find_memend_and_nodes(mi, np);
 	bootmap_pfn   = find_bootmap_pfn(0, mi, bootmap_pages);
 	initrd_node   = check_initrd(mi);

 	map_pg = bootmap_pfn;

 	/*
 	 * Initialise the bootmem nodes.
 	 *
 	 * What we really want to do is:
 	 *
 	 *   unmap_all_regions_except_kernel();
 	 *   for_each_node_in_reverse_order(node) {
 	 *     map_node(node);
 	 *     allocate_bootmem_map(node);
 	 *     init_bootmem_node(node);
 	 *     free_bootmem_node(node);
 	 *   }
 	 *
 	 * but this is a 2.5-type change.  For now, we just set
 	 * the nodes up in reverse order.
 	 *
 	 * (we could also do with rolling bootmem_init and paging_init
 	 * into one generic "memory_init" type function).
 	 */
 	np += num_online_nodes() - 1;
 	for (node = num_online_nodes() - 1; node >= 0; node--, np--) {
 		/*
 		 * If there are no pages in this node, ignore it.
 		 * Note that node 0 must always have some pages.
 		 */
 		if (np->end == 0 || !node_online(node)) {
 			if (node == 0)
 				BUG();
 			continue;
 		}

 		/*
 		 * Initialise the bootmem allocator.
 		 */
 		init_bootmem_node(NODE_DATA(node), map_pg, np->start, np->end);
 		free_bootmem_node_bank(node, mi);
 		map_pg += np->bootmap_pages;

 		/*
 		 * If this is node 0, we need to reserve some areas ASAP -
 		 * we may use bootmem on node 0 to setup the other nodes.
 		 */
 		if (node == 0)
 			reserve_node_zero(bootmap_pfn, bootmap_pages);
 	}


 #ifdef CONFIG_BLK_DEV_INITRD
 	if (phys_initrd_size && initrd_node >= 0) {
 		reserve_bootmem_node(NODE_DATA(initrd_node), phys_initrd_start,
 				     phys_initrd_size);
 		initrd_start = __phys_to_virt(phys_initrd_start);
 		initrd_end = initrd_start + phys_initrd_size;
 	}
 #endif

 	BUG_ON(map_pg != bootmap_pfn + bootmap_pages);
 }

 /*
  * paging_init() sets up the page tables, initialises the zone memory
  * maps, and sets up the zero page, bad page and bad page tables.
  */
 void __init paging_init(struct meminfo *mi, struct machine_desc *mdesc)
 {
 	void *zero_page;
 	int node;

 	bootmem_init(mi);

 	memcpy(&meminfo, mi, sizeof(meminfo));

 	/*
 	 * allocate the zero page.  Note that we count on this going ok.
 	 */
 	zero_page = alloc_bootmem_low_pages(PAGE_SIZE);

 	/*
 	 * initialise the page tables.
 	 */
 	memtable_init(mi);
 	if (mdesc->map_io)
 		mdesc->map_io();
 	flush_tlb_all();

 	/*
 	 * initialise the zones within each node
 	 */
 	for_each_online_node(node) {
 		unsigned long zone_size[MAX_NR_ZONES];
 		unsigned long zhole_size[MAX_NR_ZONES];
 		struct bootmem_data *bdata;
 		pg_data_t *pgdat;
 		int i;

 		/*
 		 * Initialise the zone size information.
 		 */
 		for (i = 0; i < MAX_NR_ZONES; i++) {
 			zone_size[i]  = 0;
 			zhole_size[i] = 0;
 		}

 		pgdat = NODE_DATA(node);
 		bdata = pgdat->bdata;

 		/*
 		 * The size of this node has already been determined.
 		 * If we need to do anything fancy with the allocation
 		 * of this memory to the zones, now is the time to do
 		 * it.
 		 */
 		zone_size[0] = bdata->node_low_pfn -
 				(bdata->node_boot_start >> PAGE_SHIFT);

 		/*
 		 * If this zone has zero size, skip it.
 		 */
 		if (!zone_size[0])
 			continue;

 		/*
 		 * For each bank in this node, calculate the size of the
 		 * holes.  holes = node_size - sum(bank_sizes_in_node)
 		 */
 		zhole_size[0] = zone_size[0];
 		for (i = 0; i < mi->nr_banks; i++) {
 			if (mi->bank[i].node != node)
 				continue;

 			zhole_size[0] -= mi->bank[i].size >> PAGE_SHIFT;
 		}

 		/*
 		 * Adjust the sizes according to any special
 		 * requirements for this machine type.
 		 */
 		arch_adjust_zones(node, zone_size, zhole_size);

 		free_area_init_node(node, pgdat, zone_size,
 				bdata->node_boot_start >> PAGE_SHIFT, zhole_size);
 	}

 	/*
 	 * finish off the bad pages once
 	 * the mem_map is initialised
 	 */
 	memzero(zero_page, PAGE_SIZE);
 	empty_zero_page = virt_to_page(zero_page);
 	flush_dcache_page(empty_zero_page);
 }

 static inline void free_area(unsigned long addr, unsigned long end, char *s)
 {
 	unsigned int size = (end - addr) >> 10;

 	for (; addr < end; addr += PAGE_SIZE) {
 		struct page *page = virt_to_page(addr);
 		ClearPageReserved(page);
 		set_page_count(page, 1);
 		free_page(addr);
 		totalram_pages++;
 	}

 	if (size && s)
 		printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
 }

 /*
  * mem_init() marks the free areas in the mem_map and tells us how much
  * memory is free.  This is done after various parts of the system have
  * claimed their memory after the kernel image.
  */
 void __init mem_init(void)
 {
 	unsigned int codepages, datapages, initpages;
 	int i, node;

 	codepages = &_etext - &_text;
 	datapages = &_end - &__data_start;
 	initpages = &__init_end - &__init_begin;

 #ifndef CONFIG_DISCONTIGMEM
 	max_mapnr   = virt_to_page(high_memory) - mem_map;
 #endif

 	/*
 	 * We may have non-contiguous memory.
 	 */
 	if (meminfo.nr_banks != 1)
 		create_memmap_holes(&meminfo);

 	/* this will put all unused low memory onto the freelists */
 	for_each_online_node(node) {
 		pg_data_t *pgdat = NODE_DATA(node);

 		if (pgdat->node_spanned_pages != 0)
 			totalram_pages += free_all_bootmem_node(pgdat);
 	}

 #ifdef CONFIG_SA1111
 	/* now that our DMA memory is actually so designated, we can free it */
 	free_area(PAGE_OFFSET, (unsigned long)swapper_pg_dir, NULL);
 #endif

 	/*
 	 * Since our memory may not be contiguous, calculate the
 	 * real number of pages we have in this system
 	 */
 	printk(KERN_INFO "Memory:");

 	num_physpages = 0;
 	for (i = 0; i < meminfo.nr_banks; i++) {
 		num_physpages += meminfo.bank[i].size >> PAGE_SHIFT;
 		printk(" %ldMB", meminfo.bank[i].size >> 20);
 	}

 	printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
 	printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
 		"%dK data, %dK init)\n",
 		(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 		codepages >> 10, datapages >> 10, initpages >> 10);

 	if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
 		extern int sysctl_overcommit_memory;
 		/*
 		 * On a machine this small we won't get
 		 * anywhere without overcommit, so turn
 		 * it on by default.
 		 */
 		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 	}
 }

 void free_initmem(void)
 {
 	if (!machine_is_integrator() && !machine_is_cintegrator()) {
 		free_area((unsigned long)(&__init_begin),
 			  (unsigned long)(&__init_end),
 			  "init");
 	}
 }

 #ifdef CONFIG_BLK_DEV_INITRD

 static int keep_initrd;

 void free_initrd_mem(unsigned long start, unsigned long end)
 {
 	if (!keep_initrd)
 		free_area(start, end, "initrd");
 }

 static int __init keepinitrd_setup(char *__unused)
 {
 	keep_initrd = 1;
 	return 1;
 }

 __setup("keepinitrd", keepinitrd_setup);
 #endif
	/*
	* linux/arch/arm/mm/init.c
	*
	* Copyright (C) 1995-2002 Russell King
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/
	#include <linux/config.h>
	#include <linux/kernel.h>
	#include <linux/errno.h>
	#include <linux/ptrace.h>
	#include <linux/swap.h>
	#include <linux/init.h>
	#include <linux/bootmem.h>
	#include <linux/mman.h>
	#include <linux/nodemask.h>
	#include <linux/initrd.h>

	#include <asm/mach-types.h>
	#include <asm/hardware.h>
	#include <asm/setup.h>
	#include <asm/tlb.h>

	#include <asm/mach/arch.h>
	#include <asm/mach/map.h>

	#define TABLE_SIZE (2 * PTRS_PER_PTE * sizeof(pte_t))

	DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);

	extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
	extern void _stext, _text, _etext, __data_start, _end, __init_begin, __init_end;
	extern unsigned long phys_initrd_start;
	extern unsigned long phys_initrd_size;

	/*
	* The sole use of this is to pass memory configuration
	* data from paging_init to mem_init.
	*/
	static struct meminfo meminfo __initdata = { 0, };

	/*
	* empty_zero_page is a special page that is used for
	* zero-initialized data and COW.
	*/
	struct page *empty_zero_page;

	void show_mem(void)
	{
	int free = 0, total = 0, reserved = 0;
	int shared = 0, cached = 0, slab = 0, node;

	printk("Mem-info:\n");
	show_free_areas();
	printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));

	for_each_online_node(node) {
	struct page page, end;

	page = NODE_MEM_MAP(node);
	end = page + NODE_DATA(node)->node_spanned_pages;

	do {
	total++;
	if (PageReserved(page))
	reserved++;
	else if (PageSwapCache(page))
	cached++;
	else if (PageSlab(page))
	slab++;
	else if (!page_count(page))
	free++;
	else
	shared += page_count(page) - 1;
	page++;
	} while (page < end);
	}

	printk("%d pages of RAM\n", total);
	printk("%d free pages\n", free);
	printk("%d reserved pages\n", reserved);
	printk("%d slab pages\n", slab);
	printk("%d pages shared\n", shared);
	printk("%d pages swap cached\n", cached);
	}

	struct node_info {
	unsigned int start;
	unsigned int end;
	int bootmap_pages;
	};

	#define O_PFN_DOWN(x) ((x) >> PAGE_SHIFT)
	#define O_PFN_UP(x) (PAGE_ALIGN(x) >> PAGE_SHIFT)

	/*
	* FIXME: We really want to avoid allocating the bootmap bitmap
	* over the top of the initrd. Hopefully, this is located towards
	* the start of a bank, so if we allocate the bootmap bitmap at
	* the end, we won't clash.
	*/
	static unsigned int __init
	find_bootmap_pfn(int node, struct meminfo *mi, unsigned int bootmap_pages)
	{
	unsigned int start_pfn, bank, bootmap_pfn;

	start_pfn = O_PFN_UP(__pa(&_end));
	bootmap_pfn = 0;

	for (bank = 0; bank < mi->nr_banks; bank ++) {
	unsigned int start, end;

	if (mi->bank[bank].node != node)
	continue;

	start = mi->bank[bank].start >> PAGE_SHIFT;
	end = (mi->bank[bank].size +
	mi->bank[bank].start) >> PAGE_SHIFT;

	if (end < start_pfn)
	continue;

	if (start < start_pfn)
	start = start_pfn;

	if (end <= start)
	continue;

	if (end - start >= bootmap_pages) {
	bootmap_pfn = start;
	break;
	}
	}

	if (bootmap_pfn == 0)
	BUG();

	return bootmap_pfn;
	}

	/*
	* Scan the memory info structure and pull out:
	* - the end of memory
	* - the number of nodes
	* - the pfn range of each node
	* - the number of bootmem bitmap pages
	*/
	static unsigned int __init
	find_memend_and_nodes(struct meminfo mi, struct node_info np)
	{
	unsigned int i, bootmem_pages = 0, memend_pfn = 0;

	for (i = 0; i < MAX_NUMNODES; i++) {
	np[i].start = -1U;
	np[i].end = 0;
	np[i].bootmap_pages = 0;
	}

	for (i = 0; i < mi->nr_banks; i++) {
	unsigned long start, end;
	int node;

	if (mi->bank[i].size == 0) {
	/*
	* Mark this bank with an invalid node number
	*/
	mi->bank[i].node = -1;
	continue;
	}

	node = mi->bank[i].node;

	/*
	* Make sure we haven't exceeded the maximum number of nodes
	* that we have in this configuration. If we have, we're in
	* trouble. (maybe we ought to limit, instead of bugging?)
	*/
	if (node >= MAX_NUMNODES)
	BUG();
	node_set_online(node);

	/*
	* Get the start and end pfns for this bank
	*/
	start = mi->bank[i].start >> PAGE_SHIFT;
	end = (mi->bank[i].start + mi->bank[i].size) >> PAGE_SHIFT;

	if (np[node].start > start)
	np[node].start = start;

	if (np[node].end < end)
	np[node].end = end;

	if (memend_pfn < end)
	memend_pfn = end;
	}

	/*
	* Calculate the number of pages we require to
	* store the bootmem bitmaps.
	*/
	for_each_online_node(i) {
	if (np[i].end == 0)
	continue;

	np[i].bootmap_pages = bootmem_bootmap_pages(np[i].end -
	np[i].start);
	bootmem_pages += np[i].bootmap_pages;
	}

	high_memory = __va(memend_pfn << PAGE_SHIFT);

	/*
	* This doesn't seem to be used by the Linux memory
	* manager any more. If we can get rid of it, we
	* also get rid of some of the stuff above as well.
	*
	* Note: max_low_pfn and max_pfn reflect the number
	* of _pages_ in the system, not the maximum PFN.
	*/
	max_low_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET);
	max_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET);

	return bootmem_pages;
	}

	static int __init check_initrd(struct meminfo *mi)
	{
	int initrd_node = -2;
	#ifdef CONFIG_BLK_DEV_INITRD
	unsigned long end = phys_initrd_start + phys_initrd_size;

	/*
	* Make sure that the initrd is within a valid area of
	* memory.
	*/
	if (phys_initrd_size) {
	unsigned int i;

	initrd_node = -1;

	for (i = 0; i < mi->nr_banks; i++) {
	unsigned long bank_end;

	bank_end = mi->bank[i].start + mi->bank[i].size;

	if (mi->bank[i].start <= phys_initrd_start &&
	end <= bank_end)
	initrd_node = mi->bank[i].node;
	}
	}

	if (initrd_node == -1) {
	printk(KERN_ERR "initrd (0x%08lx - 0x%08lx) extends beyond "
	"physical memory - disabling initrd\n",
	phys_initrd_start, end);
	phys_initrd_start = phys_initrd_size = 0;
	}
	#endif

	return initrd_node;
	}

	/*
	* Reserve the various regions of node 0
	*/
	static __init void reserve_node_zero(unsigned int bootmap_pfn, unsigned int bootmap_pages)
	{
	pg_data_t *pgdat = NODE_DATA(0);
	unsigned long res_size = 0;

	/*
	* Register the kernel text and data with bootmem.
	* Note that this can only be in node 0.
	*/
	#ifdef CONFIG_XIP_KERNEL
	reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start);
	#else
	reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
	#endif

	/*
	* Reserve the page tables. These are already in use,
	* and can only be in node 0.
	*/
	reserve_bootmem_node(pgdat, __pa(swapper_pg_dir),
	PTRS_PER_PGD * sizeof(pgd_t));

	/*
	* And don't forget to reserve the allocator bitmap,
	* which will be freed later.
	*/
	reserve_bootmem_node(pgdat, bootmap_pfn << PAGE_SHIFT,
	bootmap_pages << PAGE_SHIFT);

	/*
	* Hmm... This should go elsewhere, but we really really need to
	* stop things allocating the low memory; ideally we need a better
	* implementation of GFP_DMA which does not assume that DMA-able
	* memory starts at zero.
	*/
	if (machine_is_integrator() \|\| machine_is_cintegrator())
	res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;

	/*
	* These should likewise go elsewhere. They pre-reserve the
	* screen memory region at the start of main system memory.
	*/
	if (machine_is_edb7211())
	res_size = 0x00020000;
	if (machine_is_p720t())
	res_size = 0x00014000;

	#ifdef CONFIG_SA1111
	/*
	* Because of the SA1111 DMA bug, we want to preserve our
	* precious DMA-able memory...
	*/
	res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;
	#endif
	if (res_size)
	reserve_bootmem_node(pgdat, PHYS_OFFSET, res_size);
	}

	/*
	* Register all available RAM in this node with the bootmem allocator.
	*/
	static inline void free_bootmem_node_bank(int node, struct meminfo *mi)
	{
	pg_data_t *pgdat = NODE_DATA(node);
	int bank;

	for (bank = 0; bank < mi->nr_banks; bank++)
	if (mi->bank[bank].node == node)
	free_bootmem_node(pgdat, mi->bank[bank].start,
	mi->bank[bank].size);
	}

	/*
	* Initialise the bootmem allocator for all nodes. This is called
	* early during the architecture specific initialisation.
	*/
	static void __init bootmem_init(struct meminfo *mi)
	{
	struct node_info node_info[MAX_NUMNODES], *np = node_info;
	unsigned int bootmap_pages, bootmap_pfn, map_pg;
	int node, initrd_node;

	bootmap_pages = find_memend_and_nodes(mi, np);
	bootmap_pfn = find_bootmap_pfn(0, mi, bootmap_pages);
	initrd_node = check_initrd(mi);

	map_pg = bootmap_pfn;

	/*
	* Initialise the bootmem nodes.
	*
	* What we really want to do is:
	*
	* unmap_all_regions_except_kernel();
	* for_each_node_in_reverse_order(node) {
	* map_node(node);
	* allocate_bootmem_map(node);
	* init_bootmem_node(node);
	* free_bootmem_node(node);
	* }
	*
	* but this is a 2.5-type change. For now, we just set
	* the nodes up in reverse order.
	*
	* (we could also do with rolling bootmem_init and paging_init
	* into one generic "memory_init" type function).
	*/
	np += num_online_nodes() - 1;
	for (node = num_online_nodes() - 1; node >= 0; node--, np--) {
	/*
	* If there are no pages in this node, ignore it.
	* Note that node 0 must always have some pages.
	*/
	if (np->end == 0 \|\| !node_online(node)) {
	if (node == 0)
	BUG();
	continue;
	}

	/*
	* Initialise the bootmem allocator.
	*/
	init_bootmem_node(NODE_DATA(node), map_pg, np->start, np->end);
	free_bootmem_node_bank(node, mi);
	map_pg += np->bootmap_pages;

	/*
	* If this is node 0, we need to reserve some areas ASAP -
	* we may use bootmem on node 0 to setup the other nodes.
	*/
	if (node == 0)
	reserve_node_zero(bootmap_pfn, bootmap_pages);
	}


	#ifdef CONFIG_BLK_DEV_INITRD
	if (phys_initrd_size && initrd_node >= 0) {
	reserve_bootmem_node(NODE_DATA(initrd_node), phys_initrd_start,
	phys_initrd_size);
	initrd_start = __phys_to_virt(phys_initrd_start);
	initrd_end = initrd_start + phys_initrd_size;
	}
	#endif

	BUG_ON(map_pg != bootmap_pfn + bootmap_pages);
	}

	/*
	* paging_init() sets up the page tables, initialises the zone memory
	* maps, and sets up the zero page, bad page and bad page tables.
	*/
	void __init paging_init(struct meminfo mi, struct machine_desc mdesc)
	{
	void *zero_page;
	int node;

	bootmem_init(mi);

	memcpy(&meminfo, mi, sizeof(meminfo));

	/*
	* allocate the zero page. Note that we count on this going ok.
	*/
	zero_page = alloc_bootmem_low_pages(PAGE_SIZE);

	/*
	* initialise the page tables.
	*/
	memtable_init(mi);
	if (mdesc->map_io)
	mdesc->map_io();
	flush_tlb_all();

	/*
	* initialise the zones within each node
	*/
	for_each_online_node(node) {
	unsigned long zone_size[MAX_NR_ZONES];
	unsigned long zhole_size[MAX_NR_ZONES];
	struct bootmem_data *bdata;
	pg_data_t *pgdat;
	int i;

	/*
	* Initialise the zone size information.
	*/
	for (i = 0; i < MAX_NR_ZONES; i++) {
	zone_size[i] = 0;
	zhole_size[i] = 0;
	}

	pgdat = NODE_DATA(node);
	bdata = pgdat->bdata;

	/*
	* The size of this node has already been determined.
	* If we need to do anything fancy with the allocation
	* of this memory to the zones, now is the time to do
	* it.
	*/
	zone_size[0] = bdata->node_low_pfn -
	(bdata->node_boot_start >> PAGE_SHIFT);

	/*
	* If this zone has zero size, skip it.
	*/
	if (!zone_size[0])
	continue;

	/*
	* For each bank in this node, calculate the size of the
	* holes. holes = node_size - sum(bank_sizes_in_node)
	*/
	zhole_size[0] = zone_size[0];
	for (i = 0; i < mi->nr_banks; i++) {
	if (mi->bank[i].node != node)
	continue;

	zhole_size[0] -= mi->bank[i].size >> PAGE_SHIFT;
	}

	/*
	* Adjust the sizes according to any special
	* requirements for this machine type.
	*/
	arch_adjust_zones(node, zone_size, zhole_size);

	free_area_init_node(node, pgdat, zone_size,
	bdata->node_boot_start >> PAGE_SHIFT, zhole_size);
	}

	/*
	* finish off the bad pages once
	* the mem_map is initialised
	*/
	memzero(zero_page, PAGE_SIZE);
	empty_zero_page = virt_to_page(zero_page);
	flush_dcache_page(empty_zero_page);
	}

	static inline void free_area(unsigned long addr, unsigned long end, char *s)
	{
	unsigned int size = (end - addr) >> 10;

	for (; addr < end; addr += PAGE_SIZE) {
	struct page *page = virt_to_page(addr);
	ClearPageReserved(page);
	set_page_count(page, 1);
	free_page(addr);
	totalram_pages++;
	}

	if (size && s)
	printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
	}

	/*
	* mem_init() marks the free areas in the mem_map and tells us how much
	* memory is free. This is done after various parts of the system have
	* claimed their memory after the kernel image.
	*/
	void __init mem_init(void)
	{
	unsigned int codepages, datapages, initpages;
	int i, node;

	codepages = &_etext - &_text;
	datapages = &_end - &__data_start;
	initpages = &__init_end - &__init_begin;

	#ifndef CONFIG_DISCONTIGMEM
	max_mapnr = virt_to_page(high_memory) - mem_map;
	#endif

	/*
	* We may have non-contiguous memory.
	*/
	if (meminfo.nr_banks != 1)
	create_memmap_holes(&meminfo);

	/* this will put all unused low memory onto the freelists */
	for_each_online_node(node) {
	pg_data_t *pgdat = NODE_DATA(node);

	if (pgdat->node_spanned_pages != 0)
	totalram_pages += free_all_bootmem_node(pgdat);
	}

	#ifdef CONFIG_SA1111
	/* now that our DMA memory is actually so designated, we can free it */
	free_area(PAGE_OFFSET, (unsigned long)swapper_pg_dir, NULL);
	#endif

	/*
	* Since our memory may not be contiguous, calculate the
	* real number of pages we have in this system
	*/
	printk(KERN_INFO "Memory:");

	num_physpages = 0;
	for (i = 0; i < meminfo.nr_banks; i++) {
	num_physpages += meminfo.bank[i].size >> PAGE_SHIFT;
	printk(" %ldMB", meminfo.bank[i].size >> 20);
	}

	printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
	printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
	"%dK data, %dK init)\n",
	(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
	codepages >> 10, datapages >> 10, initpages >> 10);

	if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
	extern int sysctl_overcommit_memory;
	/*
	* On a machine this small we won't get
	* anywhere without overcommit, so turn
	* it on by default.
	*/
	sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
	}
	}

	void free_initmem(void)
	{
	if (!machine_is_integrator() && !machine_is_cintegrator()) {
	free_area((unsigned long)(&__init_begin),
	(unsigned long)(&__init_end),
	"init");
	}
	}

	#ifdef CONFIG_BLK_DEV_INITRD

	static int keep_initrd;

	void free_initrd_mem(unsigned long start, unsigned long end)
	{
	if (!keep_initrd)
	free_area(start, end, "initrd");
	}

	static int __init keepinitrd_setup(char *__unused)
	{
	keep_initrd = 1;
	return 1;
	}

	__setup("keepinitrd", keepinitrd_setup);
	#endif